How is the particle displacement related to the direction of wave movement in a longitudinal wave?

a.) parallel to
b.) opposite to
c.) above
d.) perpendicular to

In a longitudinal wave, the particle displacement is parallel to the direction of wave movement.

Option A

Explanation:

Longitudinal waves is defined as the way to transfer energy in a medium. As the energy is introduced in the medium, the particles in the medium will travel along the direction of wave propagation. So the energy is transferred in the form of compression and rarefaction of the particles in the medium for transfer of wave in longitudinal waves.

When energy is transferred to a region of particles in the medium, the medium will exhibit compression and when the energy travels from that region to the neighboring region, the previous region will undergo rarefaction. Like this way, the particles in the medium will get displaced parallel to the wave movement in longitudinal wave.

car stops. he keeps going = he has inertia